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Blog Title: How do I identify limit switches for an air conditioner?

Main Que: How do I identify limit switches?

  • Category:
  • Query By: LEO BREWER (Saint Johns, TX)
  • Date: 06/18/2014

Answer: In the air handler/heater section of the furnace several limit switches help protect against accidental operation of the system. Depending on the type of system, a limit switch is installed to guarantee forced purge occurs before allowing the gas valve to open. A switch is present to insure the air is hot enough for the fan to turn on. Another switch is for the high temperature limit. Some systems will have a low and working temperature limit switch for operating the furnace. A switch on the filter door will be found on newer units. Many heat related switches are eye shaped with a raised circle in the center of the eye. The fan switch can also be a heat controlled switch. The box or mounting area will usually have a temerature guage that is settable. Momentary connection switches are used to keep panels in place.

  • Replied By: WILLIE ROGERS (Gold Hill, CA)
  • Replied Date: 06/29/2015